Batteries utilizing anode coatings directly on nanoporous separators

ABSTRACT

Provided are methods of preparing a separator/anode assembly for use in an electric current producing cell, wherein the assembly comprises an anode current collector layer interposed between a first anode layer and a second anode layer and a porous separator layer on the side of the first anode layer opposite to the anode current collector layer, wherein the first anode layer is coated directly on the separator layer.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 17/235,272, filed Apr. 20, 2021, which is a continuation ofU.S. patent application Ser. No. 17/179,090, filed Feb. 18, 2021, nowU.S. Pat. No. 11,283,137, which is a continuation of U.S. patentapplication Ser. No. 16/556,483, filed Aug. 30, 2019, now U.S. Pat. No.10,950,837, which is a continuation of U.S. patent application Ser. No.15/492,126, filed Apr. 20, 2017, now U.S. Pat. No. 10,403,874, which isa continuation of U.S. patent application Ser. No. 14/605,349, filedJan. 26, 2015, now U.S. Pat. No. 9,660,297, which is a divisional ofU.S. patent application Ser. No. 13/302,782, filed Nov. 22, 2011, nowU.S. Pat. No. 8,962,182, titled Batteries Utilizing Anode CoatingsDirectly on Nanoporous Separators that is a continuation-in-part of thefollowing applications:

-   -   (a) PCT Application No. PCT/US2010/001536, filed May 26, 2010,        which claims the benefit under 35 U.S.C. § 119(e) of U.S.        Provisional Patent Application No. 61/217,132, filed May 26,        2009;    -   (b) PCT Application No. PCT/US2010/001537, filed May 26, 2010,        which claims the benefit under 35 U.S.C. § 119(e) of U.S.        Provisional Patent Application No. 61/217,132, filed May 26,        2009;    -   (c) PCT Application No. PCT/US2010/001539, filed May 26, 2010,        which claims the benefit under 35 U.S.C. § 119(e) of U.S.        Provisional Patent Application No. 61/217,132, filed May 26,        2009; and    -   (d) PCT Application No. PCT/US2010/001535, filed May 26, 2010,        which claims the benefit under 35 U.S.C. § 119(e) of U.S.        Provisional Patent Application No. 61/217,132, filed May 26,        2009.

The entireties of each of the above-referenced patent applications areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to the field of batteries andother electric current producing cells. This invention pertains tolithium batteries that utilize nanoporous separators and to methods ofpreparing lithium batteries by taking advantage of the nanoporousstructure of the separator to overlay the other layers of the battery ina desired configuration. More particularly, the present inventionpertains to separator/anode assemblies for batteries where the anodelayer is coated directly on a porous separator layer and to methods ofpreparing such separator/anode assemblies.

BACKGROUND OF THE INVENTION

Lithium batteries, including rechargeable or secondary lithium ionbatteries, non-rechargeable or primary lithium batteries, and othertypes such as lithium-sulfur batteries, are typically made byinterleaving a plastic separator, a conductive metal substrate with acathode layer coated on both sides, another plastic separator, andanother conductive metal substrate with an anode layer coated on bothsides. To maintain the alignment of the strips of these materials andfor other quality reasons, this interleaving is usually done onautomatic equipment, which is complex and expensive. Also, in order toachieve sufficient mechanical strength and integrity, the separators andthe metal substrates are relatively thick, such as 10 microns inthickness or more. For example, a typical thickness of the copper metalsubstrate for the anode coating layers is 10 microns, a typicalthickness of the aluminum metal substrate for the cathode coating layersis 12 microns, and the plastic separators typically have thicknessesranging from 12 to 20 microns. These thick separators and metalsubstrates are not electrochemically active and thus lower the volume ofthe electroactive material in the electrodes of the lithium batteries.This limits the energy density and power density of the lithiumbatteries.

Among the new applications for lithium batteries are high powerbatteries for hybrid, plug-in hybrid, and electric vehicles. In contrastto the cylindrical metal cells used in lithium batteries for portablecomputers and other applications, many of the lithium batteries forvehicles are of a flat or prismatic design. Also, the lithium batteriesfor vehicles need to be economical. Potential approaches to make higherenergy and more economical lithium batteries for vehicles and otherapplications include greatly increasing the proportion or percentage ofthe volume of the electroactive material in each battery and reducingthe complexity and expense of the automated equipment to fabricate thebattery.

It would be advantageous if a lithium battery comprised separator andmetal substrate layers that were much thinner than are currently usedwith either or both of its cathode and anode layers and thereby had agreater content of electroactive material. It would be particularlyadvantageous if this lithium battery could be fabricated on less complexand less expensive automated processing equipment than, for example, thewinding equipment utilized for portable computer batteries, andfurthermore was particularly adapted for making flat or prismaticbatteries.

SUMMARY OF THE INVENTION

This invention pertains to lithium and other batteries and toseparator/anode assemblies for lithium and other batteries that utilizenanoporous separators, particularly heat resistant separators withdimensional stability at temperatures at and above 200° C., and tomethods of preparing lithium batteries and separator/anode assemblies,by taking advantage of the nanoporous structure of the separator layerto coat the other layers of the battery in a desired thickness andconfiguration directly on the porous separator layer.

One aspect of this invention pertains to a separator/anode assembly foruse in an electric current producing cell, wherein the assemblycomprises an anode current collector layer interposed between a firstanode layer and a second anode layer and a porous separator layer on theside of the first anode layer opposite to the anode current collectorlayer, wherein the first anode layer is coated directly on the separatorlayer. In one embodiment of the separator/anode assembly, no separatorlayer is coated directly on the second anode layer. In one embodiment,the surface of the first anode layer adjacent to the top surface of theseparator layer has a contour matching the contour of the top surface ofthe separator layer, and the contour of the top surface of the separatorlayer is the same as before the coating of the first anode layerdirectly on the separator layer.

In one embodiment of the separator/anode assemblies of this invention,the first anode layer comprises anode particles selected from the groupconsisting of electroactive particles and electrically conductiveparticles, and the anode particles are not present in the separatorlayer. In one embodiment, the separator layer comprises separatorparticles, and the separator particles are not present in the firstanode layer. In one embodiment, the separator particles are selectedfrom the group consisting of inorganic oxide particles, inorganicnitride particles, inorganic carbonate particles, inorganic sulfateparticles, and polymer particles.

In one embodiment of the separator/anode assemblies of the presentinvention, the anode current collector layer of the assembly comprises acopper layer. In one embodiment, the thickness of the copper layer isless than 3 microns.

In one embodiment of the separator/anode assemblies of this invention,the separator layer comprises pores having an average pore diameter ofless than 0.2 microns, and preferably less than 0.1 microns. In oneembodiment, the separator layer has a thickness of less than 9 microns,and preferably less than 6 microns. In one embodiment, the separatorcomprises a porous layer comprising aluminum boehmite.

Still another aspect of this invention pertains to a separator/anodeassembly for use in an electric current producing cell, wherein theseparator/anode assembly comprises an anode layer and a porous separatorlayer on one side of the anode layer, and wherein the anode layer iscoated directly on the separator layer. In one embodiment, the anodelayer comprises lithium metal.

Another aspect of the present invention pertains to methods of making aseparator/anode assembly for use in an electric current producing cellcomprising the steps of (a) providing a porous separator layer; (b)coating a first anode layer directly on the separator layer; and (c)coating one or more anode current collector layers directly on the firstanode layer to make the separator/anode assembly. In one embodiment,after step (c), there is a further step (d) of coating a second anodelayer directly on the one or more anode current collector layers. In oneembodiment, step (a) comprises coating a porous separator on asubstrate. In one embodiment, the substrate is a release substrate, and,after step (c), there is a further step (d) of delaminating thesubstrate from the separator layer to form the separator/anode assembly.In one embodiment, after step (c) and prior to step (d), there is afurther step of coating a second anode layer directly on the one or moreanode current collector layers. In one embodiment, the substrate is aporous substrate. In one embodiment, the porous substrate is selectedfrom the group consisting of porous polymer films and porous non-wovenpolymer fiber substrates.

In one embodiment of the methods of making separator/anode assemblies ofthis invention, the one or more anode current collector layers of step(c) comprises a metal layer and the thickness of the metal layer is lessthan 3 microns. In one embodiment, the separator layer comprises poreshaving an average pore diameter of less than 0.2 microns, and preferablyless than 0.1 microns. In one embodiment, the separator layer has athickness of less than 9 microns, and preferably less than 6 microns.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, particular arrangementsand methodologies are shown in the drawings. It should be understood,however, that the invention is not limited to the precise arrangementsshown or to the methodologies of the detailed description.

FIG. 1 shows a cross-section view of a separator/anode assembly afterone version of the steps to make a separator/anode assembly.

FIG. 2 shows a cross-section view of a separator/anode assembly afteranother version of the steps to make a separator/anode assembly.

DETAILED DESCRIPTION OF THE INVENTION

The separator/anode assemblies and methods of preparing separator/anodeassemblies of the present invention provide a flexible and effectiveapproach to separator/anode assemblies and to lithium and otherbatteries incorporating such separator/anode assemblies, to providelithium and other batteries with higher energy and power densities andwith lower manufacturing and capital equipment costs.

One aspect of this invention pertains to a separator/anode assembly foruse in an electric current producing cell, wherein the assemblycomprises an anode current collector layer interposed between a firstanode layer and a second anode layer and a porous separator layer on theside of the first anode layer opposite to the anode current collectorlayer, wherein the first anode layer is coated directly on the separatorlayer. In one embodiment of the separator/anode assembly, no separatorlayer is coated directly on the second anode layer. In one embodiment,the surface of the first anode layer adjacent to the top surface of theseparator layer has a contour matching the contour of the top surface ofthe separator layer, and the contour of the top surface of the separatorlayer is the same as before the coating of the first anode layerdirectly on the separator layer.

As used herein, the word “battery” pertains to both a single electriccurrent producing cell and to multiple electric current producing cellscombined in a casing or pack. As used herein, the term “lithium battery”refers to all types of lithium batteries known in the art, including,but not limited to, rechargeable or secondary lithium ion batteries,non-rechargeable or primary lithium batteries, and other types such aslithium-sulfur batteries.

As used herein, the term “current collector layer” refers to one or morecurrent collection layers that are adjacent to an electrode layer. Thisincludes, but is not limited to, a single conductive metal layer orsubstrate and a single conductive metal layer or substrate with anoverlying conductive coating layer, such as a carbon black-based polymercoating layer. Examples of a conductive metal substrate as the currentcollector are a metal substrate comprising aluminum, which is typicallyused as the current collector and substrate for the positive electrodeor cathode layer, and a metal substrate comprising copper, which istypically used as the current collector and substrate for the negativeelectrode or anode layer. The anode current collector layer may comprisean electrically conductive material selected from the group consistingof electrically conductive metals including metal pigments or particles,electrically conductive carbons including carbon black and graphitepigments, and electrically conductive polymers. These electricallyconductive materials may be combined with an organic polymer for addedmechanical strength and flexibility to form the anode current collectorlayer.

As used herein, the term “electrode layer” refers to a layer of the cellthat comprises electroactive material. When the electrode layer is wherethe lithium is present in the case of primary lithium batteries or, inthe case of rechargeable lithium batteries, is formed during thecharging of the battery and is oxidized to lithium ions during thedischarging of the battery, the electrode layer is called the anode ornegative electrode. The other electrode of opposite polarity is calledthe cathode or positive electrode. Any of the electroactive materialsthat are useful in lithium batteries may be utilized in the electrodelayers of this invention. Examples include, but are not limited to,lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate,and sulfur as electroactive materials in the cathode layers and lithiumtitanate, lithium metal, lithium-intercalated graphite, andlithium-intercalated carbon as electroactive materials in the anodelayers.

As used herein, the word “electrolyte” refers to any of the electrolytesthat are useful in lithium batteries. Suitable electrolytes include, butare not limited to, liquid electrolytes, gel polymer electrolytes, andsolid polymer electrolytes. Suitable liquid electrolytes include, butare not limited to, LiPF₆ solutions in a mixture of organic solvents,such as, for example, a mixture of ethylene carbonate, propylenecarbonate, and ethyl methyl carbonate.

FIG. 1 shows an example of a cross-section view (not to scale) of oneversion of a separator/anode assembly 30 of the present invention withfirst anode layer 36 interposed between anode current collector layer 34and porous separator layer 38. FIG. 2 shows an example of across-section view (not to scale) of another version of aseparator/anode assembly 40 of this invention with an anode currentcollector layer 44 interposed between a first anode layer 46 and asecond anode layer 47 and with a porous separator layer 48 on the sideof the first anode layer 46 opposite to the anode current collectorlayer 44.

In one embodiment of the separator/anode assemblies of the presentinvention, the first anode layer comprises anode particles selected fromthe group consisting of electroactive particles and electricallyconductive particles, and the anode particles are not present in theseparator layer. In one embodiment, the separator layer comprisesseparator particles, and the separator particles are not present in thefirst anode layer. In one embodiment, the separator particles areselected from the group consisting of inorganic oxide particles,inorganic nitride particles, inorganic carbonate particles, inorganicsulfate particles, and polymer particles.

In one embodiment of the separator/anode assemblies of this invention,the separator layer comprises pores with an average pore diameter ofless than 0.2 microns, and preferably less than 0.1 microns. In oneembodiment, the separator layer has a pore diameter of less than 0.2microns, and preferably less than 0.1 microns. In one embodiment, theseparator layer has a thickness of less than 9 microns, and preferablyless than 6 microns. In one embodiment, the porous separator layercomprises a porous layer comprising a xerogel layer or xerogel membrane.In one embodiment, the porous separator layer comprises aluminumboehmite. In one embodiment, the separator layer is a heat resistantseparator layer with dimensional stability at 200° C. and higher.

By the term “xerogel layer”, as used herein, is meant a porous layerthat was formed by a xerogel or sol gel process of drying a colloidalsol liquid to form a solid gel material. By the term “xerogel membrane”,as used herein, is meant a membrane that comprises at least one layercomprising a xerogel layer where the pores of the xerogel layer arecontinuous from one side of the layer to the other side of the layer.Xerogel layers and membranes typically comprise inorganic oxidematerials, such as aluminum oxides, aluminum boehmites, and zirconiumoxides, as the sol gel materials. Examples of suitable xerogel membranesfor the present invention include, but are not limited to, xerogelmembranes described in U.S. Pat. Nos. 6,153,337 and 6,306,545 to Carlsonet al. and U.S. Pat. Nos. 6,488,721 and 6,497,780 to Carlson.

Still another aspect of this invention pertains to a separator/anodeassembly for use in an electric current producing cell, wherein theseparator/anode assembly comprises an anode layer and a porous separatorlayer on one side of the anode layer, and wherein the anode layer iscoated directly on the separator layer. In one embodiment, the anodelayer comprises lithium metal. With some anode layers, such as, forexample, those that are highly electrically conductive and contain ahigh content of lithium or an alloy of lithium or of anotherelectroactive anode metal or metal alloy, an anode current collectorlayer may not be required. In these cases, the steps of coating theanode current collector layer and coating the second anode layer may beeliminated, and the first anode layer may be coated directly on theporous separator layer. This coating of the first anode layer may be avapor deposition of the lithium or other metal composition of the anodelayer or may be a coating or deposition by any of the other methodsknown in the art of metal anode layers for lithium batteries. Examplesof lithium batteries that may not require an anode current collectorlayer and a second anode layer in the separator/anode assembly includelithium-sulfur batteries where the anode is typically a layer of lithiummetal. If additional battery layers need to be coated on one or bothsides of the lithium or other metal anode layer for batterystabilization during cycling and for other reasons, these additionallayers may be coated in additional coating steps directly on theseparator layer or on the metal anode layer. In cases where there areadditional coating steps to form non-anode active layers on theseparator layer, the anode layer may be coated on these additionalnon-anode active layers

Examples of suitable separator coating layers for the present inventioninclude, but are not limited to, the separator coatings described inU.S. Pat. Nos. 6,153,337 and 6,306,545 to Carlson et al. and U.S. Pat.Nos. 6,488,721 and 6,497,780 to Carlson. These separator coatings may becoated from an aqueous mix or a solvent mix onto a variety ofsubstrates, such as, for example, silicone-treated plastic and papersubstrates, polyester film substrates, polyolefin-coated papers, andmetal substrates, and, alternatively, porous substrates such as, forexample, porous plastic films and porous non-woven polymer fibersubstrates. The advantages of coating the separator onto a substrate forthis invention include, but are not limited to, (a) that the otherlayers of the lithium battery may be coated or laminated overlying thisseparator coating layer and then subsequently the substrate may beremoved by delaminating to provide a dry stack of battery layers, or,alternatively, the substrate may be porous and may be used without anydelaminating step, (b) the coating process for the separator layer lendsitself to making thinner separators than are typically available from anextrusion process for the separator, and (c) the coated separator layermay be nanoporous with pore diameters of less than 0.1 microns that aretoo small to allow any penetration of the particles of the electrode andother overlying coating layers into the separator layer. Even separatorlayers with pore diameters up to 0.2 microns have been found to preventthe penetration into the separator layer of any particles of carbonblack pigments as are typically used in lithium batteries.

The electrode coating layer may be coated on the full surface of theseparator layer, or in lanes or strips on the separator layer, or inpatches or rectangle shapes on the separator layer, depending on therequirements of the end use and the specific approach to doing thecurrent collection from the layers of each electrode without having ashort circuit due to contacting any layers of the electrode and currentcollector of opposite polarity. Cathode coating layers typically arecoated from a pigment dispersion comprising an organic solvent, such asN-methyl pyrrolidone (NMP), and contain the electroactive or cathodeactive material in a pigment or particle form, a conductive carbonpigment, and an organic polymer. Anode coating layers typically arecoated from a pigment dispersion comprising an organic solvent or water,and contain the electroactive or anode active material in a pigment orparticle form, a conductive carbon pigment, and an organic polymer.These electrode pigments are particles with diameters typically greaterthan 0.1 microns and often in the range of 0.5 to 5 microns.

However, both the cathode and anode layers may be coated in aseparator/electrode assembly and those assemblies combined to form a dryseparator/electrode cell. In this case, the separator layer may bepresent on all of the electrode layers to give a “double separator”layer between the cathode and anode layers or, alternatively, may bepresent on only one electrode side of the separator/electrode assembly.

In one embodiment of the separator/anode assemblies of this invention,the anode current collector layer comprises a copper layer. In oneembodiment, the thickness of the copper layer is less than 3 microns.

For the current collector layer, alternatively, a conductivenon-metallic layer, such as a carbon pigment coating, as known in theart of lithium batteries, may be coated before and/or after thedeposition of the metal current collector layer in order to achieveimproved current collection and battery efficiency, as well as providingsome added mechanical strength and flexibility. The metal currentcollector layer may be much thinner than the typically 10 to 12 micronthick metal substrates used in lithium batteries. For example, the metalcurrent collector layer may have a thickness of less than 3 microns, andmay be as thin as about 1 micron, such as in the range of 0.5 to 1.5microns thick. This allows a higher proportion of electroactive materialinto the lithium battery, thereby enhancing the energy and powerdensities of the lithium battery. The metal current collector layer maybe deposited by any of the metal deposition methods known in the art,such as by vacuum deposition in the case of copper layers.

In one embodiment of the separator/anode assemblies of this invention,the current collector layer is coated directly on the first anode layeron the side opposite to the separator layer. In one embodiment, thecurrent collector layer comprises an electrically conductive materialselected from the group consisting of electrically conductive metalsincluding metal pigments or particles, electrically conductive carbonsincluding carbon black and graphite pigments, and electricallyconductive polymers. These electrically conductive materials may becombined with an organic polymer for added mechanical strength andflexibility to form the anode current collector layer. In oneembodiment, the anode current collector layer comprises a copper layer.In one embodiment, the thickness of the copper layer is less than 3microns. In one embodiment, the electrically conductive materialcomprises copper. In one embodiment, the anode current collector layercomprises two or more layers coated directly on the first anode layerand wherein at least one of the two or more current collector layerscomprises an electrically conductive material comprising carbon.

In one embodiment of the separator/anode assemblies of this invention,the thickness of the current collector layer is less than 3 microns. Inone embodiment, the thickness of the current collector layer is from 0.5to 1.5 microns. In one embodiment, the second anode layer is coateddirectly on the current collector layer on the side opposite to thefirst anode layer.

Another aspect of the present invention pertains to a battery comprisinga separator/anode assembly, wherein the assembly comprises an anodecurrent collector layer interposed between a first anode layer and asecond anode layer and a porous separator layer on the side of the firstanode layer opposite to the current collector layer, wherein the firstanode layer is coated directly on the separator layer. In oneembodiment, the battery is a lithium battery.

Another aspect of the present invention pertains to methods of making aseparator/anode assembly for use in an electric current producing cellcomprising the steps of (a) providing a porous separator layer; (b)coating a first anode layer directly on the separator layer; and (c)coating one or more anode current collector layers directly on the firstanode layer to make the separator/anode assembly. In one embodiment,after step (c), there is a further step (d) of coating a second anodelayer directly on the one or more anode current collector layers. In oneembodiment, step (a) comprises coating a porous separator layer on asubstrate. In one embodiment, the substrate is a release substrate, and,after step (c), there is a further step (d) of delaminating thesubstrate from the separator layer to form the separator/anode assembly.In one embodiment, after step (c) and prior to step (d), there is afurther step of coating a second anode layer directly on the one or moreanode current collector layers. In one embodiment, the substrate is aporous substrate. In one embodiment, the porous substrate is selectedfrom the group consisting of porous polymer films and porous non-wovenpolymer fiber substrates.

Examples of a porous substrate include, but are not limited to, porouspolyethylene films and porous polypropylene films such as, for example,are sold under the trade name of CELGARD by Polypore, Inc., Charlotte,N.C. In order to minimize the overall thickness of the separator layer,the porous substrate may be 5 to 12 microns in thickness and the porousseparator layer coated on the porous substrate may be 2 to 10 microns inthickness. If the porous substrate has sufficient mechanical strength tobe handled on the coating equipment as a free standing film or by theuse of a temporary release liner and has the properties needed for alithium battery separator, the use of a porous substrate in step (a)eliminates the need for a later delamination step because the poroussubstrate becomes a layer of the battery and functions as a separator.The porous separator layer coated directly on the porous substrate hasthe benefits of providing a layer of very small pores that prevents thepenetration of any of the particles of the electrode layer directlycoated on it and, if a heat resistant separator layer comprisingaluminum boehmite or another non-melting material is used, has the addedbenefits of providing a safer and more heat resistant separator withdimensional stability at and above 200° C.

In one embodiment of the methods of preparing separator/anode assembliesof this invention, the one or more anode current collector layers ofstep (c) comprise a metal layer and the thickness of the metal layer isless than 3 microns. In one embodiment, the separator layer comprisespores having an average pore diameter of less than 0.2 microns, andpreferably less than 0.1 microns. In one embodiment, the separator layerhas a thickness of less than 9 microns, and preferably less than 6microns.

FIG. 1 shows an example of a cross-section view (not to scale) of oneversion of a separator/anode assembly 30 of this invention after steps(a), (b), and (c). Separator/anode assembly 30 comprises a porousseparator layer 38, a first anode layer 36, and an anode currentcollector layer 34. FIG. 2 shows an example of a cross-section view (notto scale) of another version of a separator/anode assembly 40 of thepresent invention after steps (a), (b), (c), and (d) of coating a secondanode layer. Separator/anode assembly 40 comprises a porous separatorlayer 48, a first anode layer 46, an anode current collector layer 44,and a second anode layer 47.

In one embodiment of the methods of preparing separator/anode assembliesof this invention, the one or more anode current collector layers ofstep (c) comprise a metal layer and the thickness of the metal layer isless than 3 microns, and preferably is about 1 micron, such as in therange of 0.5 to 1.5 microns. In one embodiment, the separator comprisespores having an average pore diameter of less than 0.2 microns, andpreferably less than 0.1 microns. In one embodiment, the separator has athickness of less than 9 microns, and preferably less than 6 microns.

What is claimed is:
 1. A lithium battery comprising: an anode layercomprising a pigment dispersion, wherein said pigment dispersioncomprises an organic solvent, an anode active material in pigment form,and a conductive carbon pigment; a porous separator layer, wherein saidporous separator layer is selected so that there is no penetration ofsaid conductive carbon pigment into said porous separator layer; and ananode current collector, wherein said anode layer is disposed betweensaid porous separator layer and said anode current collector.
 2. Thelithium battery of claim 1, wherein said porous separator layer isselected so that there is no penetration of said anode active materialinto the porous separator layer.
 3. The lithium battery of claim 1,wherein said porous separator layer has an average pore diameter that issmaller than the average diameter of said anode active material inpigment form.
 4. The lithium battery of claim 1, wherein said porousseparator layer has an average pore diameter that is smaller than theaverage diameter of said conductive carbon pigment.
 5. The lithiumbattery of claim 1, wherein said anode current collector comprises ametal.
 6. The lithium battery of claim 1, wherein said anode activematerial in pigment form has a diameter between 0.5 to 5 microns.
 7. Thelithium battery of claim 1, wherein said anode layer has a contour thatmatches the contour of the said porous separator layer.
 8. A lithiumbattery comprising: an anode layer comprising a pigment dispersion,wherein said pigment dispersion comprises an organic solvent or water,an anode active material in pigment form, and a conductive carbonpigment; wherein said anode active material in pigment form has adiameter between 0.5 to 5 microns; a porous separator layer, whereinsaid porous separator layer has an average pore diameter that is lessthan 0.2 microns; and an anode current collector, wherein said anodelayer is disposed between said porous separator layer and said anodecurrent collector.
 9. The lithium battery of claim 8, wherein saidporous separator layer has an average pore diameter that is less than0.1 microns.
 10. The lithium battery of claim 8, wherein said anodecurrent collector layer comprises a metal.
 11. The lithium battery ofclaim 8, wherein said porous separator layer is selected so that thereis no penetration of said anode active material into the porousseparator layer.
 12. The lithium battery of claim 8, wherein said porousseparator layer is selected so that there is no penetration of saidconductive carbon pigment into said porous separator layer.
 13. Thelithium battery of claim 8, wherein said porous separator layer has anaverage pore diameter that is smaller than the average diameter of saidanode active material in pigment form.
 14. The lithium battery of claim8, wherein said porous separator layer has an average pore diameter thatis smaller than the average diameter of said conductive carbon pigment.15. The lithium battery of claim 8, wherein said anode layer has acontour that matches the contour of the said porous separator layer. 16.A lithium battery comprising: an anode layer comprising a pigmentdispersion, wherein said pigment dispersion comprises an organicsolvent, an anode active material in pigment form, and a conductivepigment; a porous separator layer, wherein said porous separator layeris selected so that there is no penetration of said conductive pigmentinto said porous separator layer; and an anode current collector,wherein said anode layer is disposed between said porous separator layerand said anode current collector.
 17. The lithium battery of claim 16,wherein said porous separator layer is selected so that there is nopenetration of said anode active material into the porous separatorlayer.
 18. The lithium battery of claim 16, wherein said porousseparator layer has an average pore diameter that is smaller than theaverage diameter of said anode active material in pigment form.
 19. Thelithium battery of claim 16, wherein said porous separator layer has anaverage pore diameter that is smaller than the average diameter of saidconductive pigment.
 20. The lithium battery of claim 16, wherein saidanode current collector comprises a metal.
 21. The lithium battery ofclaim 16, wherein said anode active material in pigment form has adiameter between 0.5 to 5 microns.